2-Minute Neuroscience: Meningitis

Meningitis is a potentially deadly disease characterized by an inflammation of the meninges. In this video, I discuss the meninges and the pathophysiology of meningitis.

TRANSCRIPT:

The term meninges refers to 3 membranes that surround the brain and spinal cord: the dura mater, the arachnoid mater, and the pia mater. The meninges protect and provide structural support for the brain as well as contain cerebrospinal fluid. Meningitis is an inflammation of the meninges. This inflammation is typically caused by an infection, although there are non-infectious causes of meningitis as well. A variety of pathogens can cause meningitis, but the most severe cases tend to involve bacterial infections.

Although the central nervous system is separated from the bloodstream by barriers like the blood-brain barrier and blood-cerebrospinal fluid barrier, meningitis can occur when pathogens evade these types of barriers and enter the meninges. When a pathogen enters the cerebrospinal fluid, an immune response causes the inflammation that characterizes meningitis. As a consequence of the immune response, the blood-brain barrier is made more permeable. This causes an influx of white blood cells and constituents of blood plasma into the cerebrospinal fluid, which contributes to inflammation and increases the volume and viscosity of the cerebrospinal fluid. These changes contribute to the development of cerebral edema, or the accumulation of fluid in the brain, as well as to the build-up of the pressure inside the skull, known as intracranial pressure. The increased intracranial pressure can disrupt cerebral blood flow and result in damage to brain tissue. Common symptoms of meningitis include headache, neck stiffness, fever, and altered mental status, but the disease can cause serious long-term complications or death. A lumbar puncture, or spinal tap, is typically done to diagnose meningitis. Although treatment will vary depending on the cause of the disease, antibiotics are often started before a diagnosis is made if bacterial meningitis is suspected, as bacterial meningitis is typically fatal if left untreated.

REFERENCES:

Hasbun R, van de Beek D, Brouwer MC, Tunkel AR. 2010. Actue Meningitis. In: Mandell GL, Bennett JE, Dolin R, eds. Mandell, Douglas, and Bennett’s Principles and Practice of Infectious Diseases, 7th ed. Philadelphia: Elsevier.

Kurrus TA, Tauber MG. 2012. Meningitis. In: Jong EC, Stevens DL, eds. Netter’s Infectious Diseases. Philadelphia: Elsevier.

Sáez-Llorens X, McCracken GH Jr. Bacterial meningitis in children. Lancet. 2003;361(9375):2139-2148. doi:10.1016/S0140-6736(03)13693-8

Scheld WM, Koedel U, Nathan B, Pfister HW. Pathophysiology of bacterial meningitis: mechanism(s) of neuronal injury. J Infect Dis. 2002;186 Suppl 2:S225-S233. doi:10.1086/344939

[dailydoseofmedicinee]

For a definitive diagnosis of meningitis, you'll need a spinal tap to collect cerebrospinal fluid (CSF). In people with meningitis, the CSF often shows a low sugar (glucose) level along with an increased white blood cell count and increased protein👍

[easymodenerd]

I had meningococcal meningitis when I was 9 months old and was hospitalized for two months. I obviously don't remember the event but its very interesting learning about it now as an adult. Thanks for the info👍

[Chris-vlfn]

I once had a morphine overdose that had been misdiagnosed by the neurological surgeon as bacterial meningitis. Very interesting and informative!

[katzrantz]

Mumps set off meningitis and encephalitis for me. Worst pain I've ever experienced and can still remember it 40+ years later.

[dragonicroblox]

just got a meningitis shot today, hurt like a bitch but i’m glad it happened

[aamirrazak]

Great video! Would love to see a future video on prion diseases like CJD

[myelinsheathxd]

I heard from my brother that his friend was dead by meningitis because he washed his head at the morning, and contribute the infection by the cold !

[anothercomment]

I won't watch this type of presentation with distractive cartoon hands darting all over the place. Sorry, millennials.